Push-button switch



June 14, 1949. P, Huw 2,473,252

' .rusa-BUTTON. swITcH Filed May 9, 1947 3 gil@ A Inventor:

by'w

. is Attorney' nieuwe Jut. 14, 1949 OFFICE rUsn-nu'rrou swrrcn ramp nua, Mums, conn., signor to General Electric Company, a corporation of New York Application May 9, 1947, Serial No. 746,811

-The present invention relates to .electric switches and more particularly to jelectric switches of the push button or plunger type. Still more particularly, the present invention relates to electric push button-switches especially adapted for installation in or adjacent to a door frame for operation by the opening or closing of the door.

It is an object of my invention to provide a push button switch of the above type which shall be reliable in operation and which at the same time can be manufactured at a low cost. It is a further object of my invention to provide 4such a an exterior elevation of my switch together with the mounting elements therefor separated from each other; Fig. 2 shows an enlarged view of my switch mounted in a panel with some partsin elevation and some partsV in section; Fig. 3 is a rear end elevation of my switch; Fig. 4 is a transverse section taken along the line 4-4 in Fig. 2; Fig. 5 is a longitudinal section taken 4along` the line 5-5 in Fig. 2; Fig. 6 is a transverse section taken along the line 8 8 in Fig. 5; and Fig. 7 is a perspective detail of the stationary contacts My switch comprises a housing l of insulating material having recesses 2, 8 and 9 therein closed by a cover plate 3. The housing I at the end opposite the recesses is-shaped to provide a cylindrical neck portion 4, in the center of which is an aperture 5 communicating with recess 2 and axially aligned therewith. 'I'he main body of the housing I has a more or less cylindrical central portion and two oppositely disposed projections 8 and 1 (Fig. 6), which provide shoulders or abutments adjacent the neck 4. The ,recess 2 in the housing has a central circular portion communicating with rectangular recesses 8, 8 in the projections 8, 'l so that the housing wall oneach side definesa pair of opposed, inwardly extending ridges III, Il and I2, I3 between the and rectangular recesses.-

Stationary contacts I4 and I 5 formed of flat strip material are provided with slots which just nt over the ridges. The portions of the contacts I4 and I5 which project into the cylindrical recess are arcuate in shape so as to t against the interior wall of the cylindrical recess and to present, toward the center of the recess, arcuate edges for contact by the movable contact element I 6.

The movable contact I8 is a ring havingI a cycylindrical 2 lindrlcal portion and "an inwardly extending truste-conical portion. -The ring is fitted over the enlarged and correspondingly shaped end of a plunger or push button I1.

The plunger Il is adapted to ilt rather loosely into the aperture 5 in the neck portion 4 of the .housing and to project out of the same for `the v loperation of the switch. The plunger I'I is axially recessed to accommodate a coil spring I8, the other end of whichpresses against the cover 3. The spring I8 thereby presses the movable contact I6 against the stationary contacts 4 and I5, whereby a circuit to which the stationary contacts may be connected is maintained normally closed.

Circuit connection to the switch is made to the contacts I4 and I5. These contact'elements have portions extending at right angles to the contact portions provided with ears I9 into which the exposed ends of insulated conductors 20 and 2| are fastened, as by soldering. The right angle portions of the contactl elements are further provided with ears 22 of greater width than the ea'rs I3 and proportioned to fit closely into the rectangular apertures 8, 9, whereby support is obtained for holding the stationary contacts in place in the switch housing. The ears 22 on each contact element also form a channel which is adaptedto receive a short insulated portion of the conductors 2li and 2 I.

In assembling my switch, the stationary contactswith the conductors attached are slid into the rectangular recesses 8, 8 in engagement with the ridges III, Il and I2, I3 and against the shoulders 23 at the bottom of the recesses. Then the plunger Il is inserted through the recess 2 and into the aperture 5 in the neck 4. After the insertion of the coll spring I8 into the plunger, the cover 3 is placed overvthe recesses and the clip 24 snapped into place to hold the assembly together.

The cover 3 is held in place by a Uggshaped clip 24 having T-shaped ends 25 which t into aA T- shaped depression in the outer surface of the housing I. y

For the mounting of my switch I provide two i additional elements, a bayonet-slotted bushing 28 and a coll spring 29. The interior of the aperture 5 in the neck portion 4 vof the housingis provided with a plurality of inwardly extending projections 21 which are adapted to be engaged by the bayonet slots 30 in the bushing 28. Toy

mount the switch in any desired wall or panel 28, a hole is drilled in the panel 28 to have a diameter equal to the outside diameter of the lrA 3 bushing 2B which lits over the plunger i1. The coll spring 29 is slipped over the neck 4 of the switch to abut the projections 6. 1 on the housing. The switch assembly, with the coll spring 29 in place, is mounted from the rear of the panel by passing the plunger il through the hole in the panel and then slipping the bushing 28 over the plunger i1 from the opposite side of the panel so that the bayonet slots of the bushing engage the projecticnsll. The assembly is locked into place by turning the bushing relative to the switch until the bayonet slots are locked around the projections 21.

It will be observed lthat by this simple mounting the switch is at all times held ilrmly in position. The spring 29 keeps a continuous tension on the bayonet lock so that vibration of the panel 26 will not cause a separation between the bushing and the switch. Moreover, the coil spring and bayonet-slotted bushing make it possible to accomodate a relatively large range of thicknesses of mounting panel 2E.

It should also be noted that by reason of th design of my at, arcuate, stationary contacts engaged by a movable contact in the form of a rather loosely mounted {ruste-conical ring, no great accuracy is required in the position of the stationary contacts. Moreover, since the movable contact is in a form of a ring and since the plunger i1 is free to turn and will turn more or less when actuated, as by the opening and closing of a door, the movable contact will continually present a new contact surface to the stationary contacts.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electrical switch comprising a housing having a cylindrical recess in one end thereof and a plurality of substantially rectangular recesses disposed around the side wall of said cylindrical recess and communicating therewith by longitudinal slots, the walls of said housing forming longitudinal ridges between said cylindrical and said rectangular recesses, a plurality of stationary contacts positioned ln said recesses, said contaots each having an arcuately shaped end concentrically disposed in said cylindrical recess, each of said contacts further having a portion shaped to iit into and being disposed within `one of said rectangular recesses and around the corresponding ridges, whereby said contacts may be assembled on conductor wires and slid into posi- Y tion in said recesses, said rectangular recesses and said ridges forming a guide and support for the insertion and retention in proper position of said stationary contacts, said housing having in its other end an aperture merging with said cylindrical recess, a plunger having one end .adapted to project through said aperture with dinal slots, the Walls of said housing forming'v longitudinal ridges between said cylindrical and A4 f said rectangular recesses, a plurality oi stationary contacts positioned in said recesses, each contact being formed from a strip of sheet metal and comprising, a base. a portion of said base being formed into a channel which is adapted to receive the insulated portion ci' a conductor. means for securing the barred end of said conductor to said base, an end Portion bent at approximately a right angle to said base and formed with an arcuately shaped tip concentrically disposed in said cylindrical recess, a plurality of oppositely disposed slots on both sides of said end and adjacent to said tip and shaped to t around said ridges, whereby said contacts maybe assembled on conductor wires and slid into position in said recesses. said rectangular recesses and said ridges forming a guide and support for the insertion and retention in proper position of said stationary contacts, said housing having at its other end an aperture merging with said cylindrical recess, a plunger having one end adapted to project through said aperture'with its other end in said cylindrical recess, a frusto-conical movable contact mounted on said other end ci. said plunger for engagement with the arcuate surfaces of said stationary contacts, a plate closing said recesses, and spring means within s'aid housing for pressing said movable contacts against said stationary contacts.

3. An electrical switch comprising a housing having a cylindrical recess in one end thereof and a. plurality of substantially rectangular recesses disposed around the side wall of said cylindrical recess and communicating therewith by longitudinal slots, the walls of said housing forming longitudinal ridges between said cylindrical and said rectangular recesses, a plurality of stationary contacts positioned in said recesses, each contact being formed from a strip of sheet metal and comprising, a base, a portion of said base -being formed into a channel which is adapted to receive the insulated portion of a conductor, m'eans for securing the barred end of said conductor to said base, an end portion bent at approximately a right angle to said base and formed with an arcuately shaped tip concentrically disposed in said cylindrical recess, a plurality of oppositely disposed slots on both sides of said end and adjacent to said tip and shaped to iit around said ridges, whereby said contacts may be assembled on conductor wires and slid into position in said recesses, said rectangular recesses and said ridges forming a guide and support for, the insertion and retention in proper position of said stationary contacts, said housing having at its other end an aperture merging with said cylindrical recess, and movable contact means in said recess to contact said stationary contacts.

PHILIP HU'I'I.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Han Apr. 15, 1947 

